1. Field of the Invention
The present invention relates to semiconductor packages and fabrication methods thereof, and more particularly, to a high-reliability semiconductor package and a fabrication method thereof.
2. Description of Related Art
Along with the rapid development of electronic industries, electronic products are developed towards multi-function and high performance. To meet the miniaturization requirement of semiconductor packages, wafer level packaging (WLP) technologies have been developed.
U.S. Pat. Nos. 6,452,265 and 7,202,107 provide fabrication methods of wafer-level packages. FIGS. 1A to 1E are schematic cross-sectional views showing a fabrication method of a conventional semiconductor package 1.
Referring to FIG.1A, a thermal release adhesive layer 11 is applied on a carrier 10. The thermal release tape 11 loses its adhesive property when heated.
Referring to FIG. 1B, a plurality of chips 12 are disposed on the thermal release adhesive layer 11. Each of the chips 12 has an active surface 12a with a plurality of electrode pads 120 and an inactive surface 12b opposite to the active surface 12a, and is disposed on the thermal release adhesive layer 11 via the active surface 12a thereof.
Referring to FIG. 1C, an encapsulant 13 is formed on the chips 12 and the thermal release tape 11 through molding.
Referring to FIG. 1D, the thermal release adhesive layer 11 and the carrier 10 are removed by heating, thereby exposing the active surfaces 12a of the chips 12.
Referring to FIG. 1E, a circuit structure 14 is formed on the encapsulant 13 and the active surfaces 12a of the chips 12 and electrically connected to the electrode pads 120 of the chips 12.
However, since the thermal release adhesive layer 11 is adhesive and the difference of CTEs (Coefficient of Thermal Expansion) between the thermal release adhesive layer 11 and the carrier 10 is substantial, after the encapsulant 13 is formed, warpage can easily occur to the overall structure during a thermal cycle, thus reducing the product reliability.
Further, it is difficult to uniformly coat the thermal release adhesive layer 11 on a large-sized carrier 10. Therefore, the thermal release adhesive layer is preferably coated on a small-sized carrier 10. However, in comparison to a large-sized carrier, it is more difficult for the conveying equipment (not shown) to transport such a small-sized carrier, thereby adversely affecting the production efficiency.
Therefore, how to overcome the above-described drawbacks has become critical.